USE OF PHYTASE IN BROILER CHICKEN DIETS: A REVIEW

The paper gives an overview of phytic acid in feed for broiler chickens, phytate sources in feedstuffs and also provides information about s ources of the enzyme phytase. Phytate is present in cereals, legumes and oilseeds as a st orage form of phosphorus, which contains approximately 14 ‐ 28 % phosphorus. Phytases are phosphohydrolases, and they are the only known enzymes which can initiate the s tep-wise removal of phosphate from phytate. Phytases can be derived from a number of s ources including plants, animals and microorganisms. Recent research has shown that microbial sources are more promising for the production of phytases on a commercial leve l and on cereal based feeds for broiler chickens. There are only 3 source organisms from which the most commonly encountered phytases in the animal feed industry em anate. They are Peniophora lycii (6phytase), Aspergillus niger (3-phytase) and Escherichia coli (6-phytase). Addition of phytase in broiler diets decreased phosphorus conte nt in poultry litter by 23 ‐ 30 %. Some studies reported that the microbial phytase in creased weight gain and thus feed efficacy. According to other authors, addition of p hytase reduces weight gain, feed intake, feed efficacy and percentage ash.